Those are still part of the greater San Francisco/Seattle metro areas though. As in like no one variable might explain everything, but compounding tech money with the limits of geography might just be a double whammy. And the BART isn't very good and Caltrain has limited coverage, so proximity still matters a lot. And Seattle has atrocious transit. In Chicago, living in the suburbs isn't so bad because the trains are so good (relatively).
And then add rampant NIMBYism on top of that, especially from people who bought in early, and it's a disaster for subsequent generations of would-be residents.
> San Francisco and Seattle might have more affordable housing everywhere like Chicago if there were land adjacent to the city everywhere, like in Chicago.
Sure, there can be lots of factors. But the original comment was about adjacent land -- which is present in the East Bay, South Bay, Eastside etc.
If your statement is now "these places might have more affordable housing if they had different geographies, demographics, regional economies, public policy, infrastructure investments and history", then I agree with the statement, it says almost nothing.
And then add rampant NIMBYism on top of that, especially from people who bought in early, and it's a disaster for subsequent generations of would-be residents.